I have to sell my beloved amplifiers.
«One Of A Kind» Push-pull monoblocks with extremely low-noise specially designed for Horn systems. Horns work most of the time in 0.1-1 watt range. You must have it clean.
"According to Sanders, the reason for push-pull amplifiers often not being at their best with horns is that they're normally optimized for the higher gain necessary to drive "standard" lower-sensitivity speakers, and the result with horns is too high a noise level."
Read more at http://www.stereophile.com/tubepoweramps/581/index.html#ajuATbXWF7dY4RjA.99
This amplifiers are about 14 years old. I bought them from an audiophile from Hawaii and he got them from a friend of Mike Sanders. (Quicksilver Audio owner/designer).These are the prototypes of the Horn Monos. They do share some similarities of course, but these are quite a different beast from the Horn Monos or any other QS amp for that matter.
These were hand built by Mike himself. Subsequently they have been upgraded and brought up to a much higher level of performance.
They are heavy. Aprox 35 – 40 pounds each. They are built on a Quicksilver chassis, and the screened on tube designations are not correct for these prototype amps. The transformers are huge, I mean massive, much bigger than Horn Mono Trannies. Another incredible feature is that the trannies have 3 output taps. One each for 8 ohm, 4 ohm and 1 ohm. Yes, one ohm! I am using the 8 at present, so that's what is connected. Fused Power Supply.
Here is what have been done.
Replaced signal caps from 'Quicksilver' branded, (sounded and looked like Hovland) with Multicap, this was just a night and day difference! Changed RCA's and Speaker posts to Top Line WBT. Replaced signal wire with Cardas pure (6 nines) silver run through pure teflon tubing. Installed 100uf Solen Film Cap as power supply bypass (big silver can in pic). Also replaced some generic electrolytics with Elna Cerafine, and ICW Clarity Caps.
There have been tested aprox. 15 types of caps before finding the perfect caps. The same with wire and rca. Many hours of careful listening and tweaking on them. The hiss is extremely minimal i can not hear anything with my horns. You really do not notice that there is an amplifier.
They are auto-bias, multi-tube use (kt88, kt66, 6550, el34, etc) aprox. 35 watts output.
Comes with Shuguang Treasure KT88-Z NR (400$ value alone). This gave more bass dynamic and the body to the sound. I can through el34 set as well. Not more than 1000 hours on them.
The driver tube is CBS 7247 made by Eico from 1960. Same as 12DW7. Same construction - gray plates, except one has "stirrup" D getter, the other has round getter.( one of the best you can find).
The new power chord has brought some more details in the bass and the sound overall became a bit more delicate.
My first impression was when i heard them "the silver shines how they sound". Silver on the black background.
I have heard different amplifiers (not in my system but in horn and with my material) like treshold, top line machintosh, avantgarde acoustics, voxativ 845 to name a few, so these would compete with amps that are priced $4000-$5000 and definitely you just can't find anything better at this price (as far as i know).
It is hard to show the exact walnut color (it changes with light) so i made different types of photo.
Still they look prettier in reality.
The original metallic chassis has paint loss in some places. I was going to change it. For 250-300$ you can have copper chassis.
One of a kind...Legendary designer/builder...Expensive and well executed upgrades.
Considering all what have been invested into them their value is 2500 usd.
You can get them for only 1500 usb.
For further reading you can google stereophile review of them.
PPS My ebay account is karahana45 (123 positive feedbacks)
I will charge actual shipping cost. I expect it to be about 100$ per box.